I have seen some older threads on this but nothing seems to apply to what I am seeing.

Running deluge-1.3.13-osx-x64-0 in macOS Sierra over a VPN and the VPN seems to be the issue for me. Not sure that uPNP requests are getting to the router properly (dd-wrt with uPNP turned on, no specific port forwarding).

When I turned the VPN off, the torrent started and worked fast.

Looks like I can't start a torrent with the VPN on: I have to fire it up without a VPN and then turn that on once it's started.